science writer + photographer

Why do some Olympic swimmers wear two caps?

Quartz

August 11, 2016

Every competitive swimmer has the same nemesis, and it’s not Michael Phelps or Katie Ledecky. It’s the water itself.

Combating drag from the pool motivates just about every decision a swimmer makes, from swimsuits to shaving to swim caps. Some swimmers even double up on their rubbery caps, something you may have noticed watching the Rio Olympics, as athletes adjust their headgear before leaping into the pool or peel off layers post-race.